In the application concerning the repairing of atrioventricular cardiac valves, mitral annuloplasty relays on the implant of mitral ring having fixed shape and size. During the classical mitral valve repair procedure, the surgeon sizes the mitral annulus and chooses the mitral ring accordingly. This procedure is done on the arrested heart under cardiopulmonary bypass, which is not a physiologic condition. It is only after the weaning off the cardiopulmonary bypass that it is possible to assess the quality of the mitral repair. In other words, the surgeon has to wake up the patient to verify if he succeeded in the mitral repair. If the repair fails, the patient undergoes a second surgical operation. Surgeons and cardiologists express a need in the possibility to adjust the ring after implantation. Having a mitral ring that changes its size after implantation and on a beating heart, could improve the quality of the mitral repair and overcome the annulus miss-sizing problem.
Some solutions have been found to reduce the risk of ineffective mitral annuloplasty.
U.S. Pat. No. 7,713,298 discloses an annuloplasty ring which comprises shape memory members configured to transform said annuloplasty ring from a first configuration having a first size of a ring dimension to other configurations having a size of the ring dimension, which is less than said first size. One of the drawbacks of such shape memory members is that they are responsive of changes in temperature and/or exposure to a magnetic field.
U.S. Pat. No. 5,064,431 discloses an adjustable annuloplasty ring for an orifice, comprising: a flexible fabric tube formed in the shape of a ring, means for dividing the tube into an inner channel and an outer channel which functions as a sewing flange by which the ring may be sutured to tissue surrounding the orifice, at least two drawstrings for adjusting the size and shape of the ring disposed in the inner channel, the drawstrings extending substantially around the circumference of the ring and having ends protruding from openings in the tube, each drawstring being coupled to the tube at least two separate anchor points. The size and shape of the ring may be adjusted by selectively tightening one or more ends of the drawstrings to constrict portions of the ring.
However, a main drawback of such mitral rings is that their size can be adjusted only one time after implantation.
Another drawback is that the change in ring's shape concerns the entire ring, not a part of it, therefore inducing great reduction in atrio-ventricular valve orifice area. This reduction could generate a clinical problem known as valve stenosis. Another drawback is that the change in shape is irreversible, therefore, if the ring is too tight, it could generate valve stenosis that would eventually deserve major heart surgery to be corrected.
WO 2011/011443 describes an annuloplasty ring assembly comprising a mechanical adjustment element which allows to modify a functional shape and/or size of a ring when actuated. The assembly comprises also transmission means linked with one end to the mechanical adjustment element. The assembly comprises also connecting means mounted on the other end of the transmission means, said connecting means comprising coupling means and driving means with complementary shaped coupling means. The driving means are designed to be removable and fitted into the coupling means for modifying the size/shape of the ring with the help of the driving means.
However, this document does not disclose a mechanical adjustment element which is able to move when the transmission means are actuated. This document discloses specifically a shape memory material which changes its size in response to a provided energy. In this document, the connecting means are not able to actuate the transmission means. Indeed, the transmission means are used only for an energy transmission. Additionally, the driving means are not designed for moving the mechanical adjustment element by driving into movement a movable part of the connecting means but merely to ensure an electrical connection for the energy transmission to the shape memory material.
EP 1 736 123 describes a bi-directional communication system for use with a restrictive opening device such as a gastric ring or band implanted within a patient. The device comprises means for a mechanical adjustment of the opening device which allows modifying a functional size of the ring when actuated. The system comprises also transmission means linked with one end to the opening device. The assembly comprises also connecting means mounted on the other end of the transmission means, said connecting means comprising coupling means and driving means designed to be removable and fitted into the coupling means for modifying the size of the ring. The driving means comprises for instance injection means associated to an injection port for the injection of a liquid which inflates the ring or band.
However, this document does not disclose a mechanical adjustment element which is able to move when the transmission means are actuated. This document discloses specifically a band or opening device which changes its size in response to a driving signal that inflates the band. In this document, the connecting means are not able to actuate the transmission means. Indeed, the transmission means are used only for a transmission of a liquid into the band. Additionally, the driving means are not designed for moving the mechanical adjustment element by driving into movement a movable part of the connecting means but merely to ensure that a liquid is transmitted to the band.
WO 2010/014671 describes a system for adjusting the dimensions of an adjustable implant such as a mitral valve ring in a patient's body. The system comprises an annuloplasty ring assembly comprising a mechanical adjustment element which allows to modify a functional shape and/or size of a ring when actuated. More specifically, the system comprises an adjustable ring associated with drawstrings. When the drawstrings are tensioned, the ring is deformed. However, when the drawings are tensioned, a large zone of the ring is deformed. It is not possible to deform a precise part of the ring.
WO 01/45486 relates to an urinary incontinence treatment apparatus. This document describes a ring assembly comprising a mechanical adjustment element which allows to modify a functional shape and/or size of a ring when actuated. The assembly comprises also transmission means linked with one end to the mechanical adjustment element. The assembly comprises also connecting means mounted on the other end of the transmission means, said connecting means comprising coupling means and driving means such as an electrical motor.
The described apparatus however does not comprise driving means that are designed to be removable and fitted into the coupling means for modifying the size/shape of the ring. And more precisely, the connecting means and the driving means do not comprise complementary shaped coupling means with removable cooperation for actuating the adjustment element.
Therefore there are, at the present time, no adequate solutions, whether commercial or in the literature, for a mitral ring having a size which can be changed and adjusted several times, on a regular basis, after implantation and on a beating heart.
Additionally, there are at the present time, no adequate solutions, whether commercial or in the literature, for an actuating device which provides a reliable and non definitive shape of an annuloplasty ring and which can be operated very easily.
More generally, there are at the present time, no adequate solutions, whether commercial or in the literature, for an actuating device which provides a reliable adjusting of a surgical implant which is adapted for different medical applications and which can be operated very easily.
Moreover, the known actuating devices need in the most of the cases, technically complicated driving means which increase substantially the costs of these actuating devices. By the way, there is no assurance that such driving devices will remain reliable after being housed in a human's body for a long period of time.